English

Find the area of the shaded region: - Mathematics

Advertisements
Advertisements

Question

Find the area of the shaded region:

Sum
Advertisements

Solution

∵ Diameter of complete circle = 14 cm

∴ Radius = `14/2` = 7 cm  ...`[∵ "Radius" = "Diameter"/2]`

So, area of complete circle = πr2 = `22/7 xx 7 xx 7` = 154 cm2

∵ Diameter of small circle = `7/4`cm

∴ Radius = `7/(4 xx 2) = 7/8`cm

∴ Area of two small circles = 2 × πr2

= `2 xx 22/7 xx 7/8 xx 7/8`

= `77/16`cm2

∴ Area of shaded region = Area of complete circle – Area of two small circles

= `154 - 77/16` 

= `(154 xx 16 - 77)/16`  ...[Taking LCM]

= `(2464 - 77)/16`

= `2387/16`

= `149 3/16`cm2

Hence, the area of shaded region is `149 3/16`cm2.

shaalaa.com
  Is there an error in this question or solution?
Chapter 9: Perimeter and Area - Exercise [Page 287]

APPEARS IN

NCERT Exemplar Mathematics [English] Class 7
Chapter 9 Perimeter and Area
Exercise | Q 99. | Page 287

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

Find the area of the circle in which a square of area 64 cm2 is inscribed. [Use π = 3.14] 


The diameter of a coin is 1 cm (in the following figure). If four such coins be placed on a table so that the rim of each touches that of the other two, find the area of the shaded region (Take π = 3.1416).

 


Two circular pieces of equal radii and maximum area, touching each other are cut out from a rectangular card board of dimensions 14 cm × 7 cm. Find the area of the remaining card board. (Use π = 22/7). 

 


From a thin metallic piece, in the shape of a trapezium ABCD, in which AB || CD and ∠BCD = 90°, a quarter circle BEFC is removed (in the following figure). Given AB = BC = 3.5 cm and DE = 2 cm, calculate the area of the remaining piece of the metal sheet.


If the area of a square is same as the area of a circle, then the ratio of their perimeters, in terms of π, is


The radius of a circle is 20 cm. It is divided into four parts of equal area by drawing three concentric circles inside it. Then, the radius of the largest of three concentric circles drawn is


The hour hand of a clock is 6 cm long. The area swept by it between 11.20 am and 11.55 am is


A square is inscribed in a circle. Find the ratio of the areas of the circle and the square.


The length of an arc of a circle, subtending an angle of 54° at the centre, is 16.5 cm. Calculate the radius, circumference and area of the circle.


The following figure shows a square cardboard ABCD of side 28 cm. Four identical circles of the largest possible sizes are cut from this card as shown below.

Find the area of the remaining card-board.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×